Tonga earthquakes

M6.3 earthquake 106 km NE of Hihifo, Tonga

A magnitude 6.3 earthquake struck 106 km NE of Hihifo, Tonga on Tue, Apr 7, 2015, 1:46 PM GMT+13 (00:46 UTC), 30 km (19 mi) below the surface.

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Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 6.3 (Mww, W-phase moment), strong
Magnitude from: USGS National Earthquake Information Center
Local time: Tue, Apr 7, 2015, 1:46 PM GMT+13
UTC: 2015-04-07 00:46:21 UTC
Depth: 30.0 km (18.6 mi), shallow
Epicenter: 15.168° S, 173.225° W
Region: Tonga
Felt reports: 17
Strongest shaking: IV, light shaking
PAGER alert: Green
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
6.3	Mww, W-phase moment	USGS National Earthquake Information Center	Preferred · Reviewed
6.3	Mw, moment	ISC-GEM global catalog	Final · ±0.1
6.4	Mwc, centroid moment	USGS National Earthquake Information Center	Moment tensor · Reviewed
6.2	Mwb, body-wave moment	USGS National Earthquake Information Center	Moment tensor · Reviewed

What happened

The USGS’s account of the effects of this earthquake.

Felt (III) at Pago Pago, American Samoa. Also felt at Ofu. Felt at Malua, Paepae`ala, Pu'apu'a, Tulaele and Vaipouli, Samoa.

From the USGS event page for us10001v8k. U.S. Geological Survey text and figures are in the public domain.

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: IV, light shaking
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

17 people reported to the USGS what they felt; the strongest reported shaking was IV, light shaking.

Estimated impact

The USGS PAGER system estimates deaths and economic losses from the shaking and the population and buildings exposed to it.

Alert level: Green: little or no damage or loss of life expected

Fault motion and ground failure

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Faulting: Normal
Moment magnitude: 6.3 Mww
Nodal plane 1: Strike 114°, dip 85°, rake -79°
Nodal plane 2: Strike 229°, dip 11°, rake -154°

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 7.1 km horizontally, 1.7 km in depth
Depth from: FROM_MODELING_OF_BROAD_BAND_P_WAVEFORMS
Station coverage gap: 36°
Stations used: 279

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Apia, SamoaPopulation 40,407. Forecast216 kmSW

Nearby

Within 100 km, magnitude 3.3 and up: 19 in the 60 days after this one and 16 in the 30 days before it.

After

Before

Earthquakes today Tonga earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us10001v8k (also filed as gcmt20150407004618, iscgem611020952). Read Mon, Oct 5, 2026, 2:46 PM UTC.